Relay



RELAY OriginalFiled Oct. 11, 1941 so i s4 7 3110mm 2- M r M w Patented Mar. 5, 1946 RELAY Thomas J. Judge, Rochester, N. Y., assignor to General Railway Signal Company, Rochester,

Original application October 11, 1941, Serial No.

Divided and this application September 10, 1943, Serial No. 501,817

10 Claims.

This invention relates to electrical relays and more particularly to a relay which is very quick in picking up and very slow to drop upon deenergization thereof.

There are various applications of relays, and this is particularly true in communication systems of the coded type, which require a relay which is extremely quick in picking up but is extremely slow in dropping away after deenergization thereof.

In accordance with the proposed to provide type relay with two present invention it is the usual tractive armature windings connected in series and constructed to produce different numbers of ampere turns to produce magnetization of the core of the relay, when energized from the same source of current, and to shunt out the winding of low ampere turns when the relay assumes its retracted position and to shunt out the winding of high ampere turns when the relay assumes its attracted position.

It is further proposed to provide, if desired, additional dropping retardation by the provision of a retarding winding or conducting slug on the relay core to augment the retardation effect produced by the short circuited high ampere turn winding when the relay assumes its energized position.

It is further proposed, when additional retardation is desired, to provide a half-wave rectifier connected across the two windings in series and so poled as to allow only the flow of current therethrough induced in such winding by the collapse of the magnetic flux in the magnetic core in response to the deenergization i the'relay.

Other objects, purposes and characteristic features of the invention will be in part pointed out in the specification hereinafter and will in part be obvious from the accompanying drawing in which- Fig. 1 shows conventionally a, relay embodying the present invention; and

Fig. 2 shows the same relay more diagrammatically and more clearly illustrates the size of the wire and the number of turns in each of the two windings in series.

This application is a division of my prior application, Ser. No. 414,584, filed October 11, 1941, now Patent No. 2,335,765, dated November 30, 1943.

The relay TNPPZ of the present invention, it will be noted, is of rather unusual construction. This construction has been resorted to in order to render thi relay very quick to pick up and very slow dropping. It will be noted that when over half this relay TNPP2 assumes its deenergized positlon the lower winding is short circuited through back contact 54 of this relay, whereas when it assumes its energized position its upper winding is short circuited by the front contact 54. If we assume the upper coil 50W of this relay to have a number of turns of proper size to have an ohmic resistance of 50 ohms, as has been found desirable in practice, and assume the lower winding BMW to have an ohmic resistance of 200 ohms, also used in practicing the invention, the resistance of the relay during its transient condition will have an ohmic resistance of 250 ohms because the two windings are then connected in series and are both unshunted. The relay core structure 30 is also linked with one or more rings or slugs 29 of copper or other conducting material. The action of these slugs, shown conventionally by shading in Fig. 1 and in perspective in Fig. 2, is further augmented by the action of the rectifier Rl2, which bridges the winding or windings of the relay 'I'NPPZ, connected between the inlet and outlet terminals. This rectifier allows the inductive kick of the relay to produce a sustaining current to delay the dropping of the relay. The relay is, of course, rendered quick picking up by reason of the fact that the low resistance coil 56W (upper coil) is only included in the energizing circuit when the relay is down. In other words, the relay TNPP2 is provided with a single quick pick-up feature and with three slow dropping features.

It is of course understood that if one winding of a relay has one-fourth as much resistance as another winding of this relay of the same size, and that if the same voltage i applied across these windings, one at a time, the winding of low resistance will provide twice the number of ampere turns of magn tization in the core on which they are contained as does the other winding. This is true because the winding with one-fourth the resistance of another winding of the same size must employ one-half as many turns of which each turn has half as much resistance (wire of twice cross-sectional area being employed). The net result is that four times as much current flows as many turns and produces twice as many ampere turns or magnetomotive-force. Therefore, if the low resistance coil is a 50 ohm winding having say 3500 turns of wire of a particularly cross-sectional area then the 200 ohm winding will have 7000 turns of wire having half the cross-sectional area of the wire of the low resistance winding. In other words, if the resistances of these windings are 50 ohms and 200 ohms then the number of turns will be 3500 and 7000 respectively, and assuming an applied potential of 100 volts direct current, the ampere turns will be 7000 and 3500, respectively. With the two windings effectively connected in series, as is true when the relay contact 54 is in a transient position, the resistance will be 250 ohms, the number of turns will be 10,500, the current flow will be (two-fifths) amperes and the ampere turns will be 4200. assuming an applied potential of 100 volts of direct current as before.

From this consideration it is apparent that the number of ampere turns magnetizing the relay changes from 7000 to 4200 and then to 3500 as the relay is energized and picked up. It is also apparent that the low resistance winding 50W is effective as a pick-up winding when the relay is picked up and is used as a retarding winding when the relay is dropped. The slug 29 and the half-wave rectifier RIZ, when used, produce additional retardation of dropping of the relay.

As shown the relay TNPP2 is controlled through a circuit including a front contact 32 of a suitable relay TNPZ and the back contact 3| of a code following relay CFTNZ. This relay TNPPZ is to pick up on the first closing of the contact 3| in response to a transmitted code and to hold up between successive impulses of such code.

Having thus shown only one embodiment of the present invention it should be understood that the particular embodiment selected has been selected to illustrate the nature of the invention and its principles of operation and that various changes, such as the omission of the slug, the rectifier or both, modifications and additions may be -made to the invention without departing from the spirit or scope of the invention, except as demanded by the scope of the following claims.

What I claim as new is:

l. A quick-picking-up and slow-droppin relay comprising, an armature. a core structure, two windings connected in series and contained on said core structure for magnetically operating said armature, a half-wave rectifier connected across both of said windings and so poled as to block the flow of current when said windings are energized from a source of direct current but to allow current to flow due to induction when said source of direct current. is removed, and contacts operated by said armature and closed only when said armature assumes its retracted position for shunting one of said windings.

2 A quick-picking-up and slow-dropping relay comprising, an armature, two windings connected in series for operating said armature, a half -wave rectifier connected across both of said windings, and contacts operated by said armature for shunting one of said windings when the relay is in the attracted position and shunting the other of said windings when it is in th retracted position.

3. A quick-picking-up and slow-dropping relay comprising, an armature, two windings connected in series for operating said armature, a half-wave rectifier connected across both of said windings, contacts operated by said armature for shunting one of said windings when in the attracted position and shunting the other of said windings when in the retracted position, and conducting slugs for delaying a change in the flux in said relay.

4. A quick-picking-up and slow-dropping relay comprising; an armature, two windings connected inseries for operating said armature, and contacts operated by said armature for shunting one of said windings when the relay is in its attracted position and shunting the other of said windings when the relay is in its retracted position.

5. A quick-picking-up and slow-dropping relay comprising; an armature, two windings connected in series for operating said armature, and contacts operated by said armature for shunting the high ampere turn winding when the relay is in its attracted position and shunting the low ampere turn winding when the relay is in its retracted position.

6. A quick-picking-up and slow-dropping relay comprising; an armature, two windings connected in series for operating said aramture, and contacts operated by said armature for shunting only the high ampere tum winding when the relay is in its attracted position, shuntin only the low ampere turn winding when the relay is in its retracted position, and shunting out neither of these windings when in an intermediate position.

'7. A quick-picking up and slow-dropping relay comprising; a magnetic core, a high resistance winding and a low resistance winding on said core and connected in series, an armature, and contacts operated by said armature to shunt said low resistance winding when said armature is in its attracted position and to shunt said high resistance winding when said armature is in its retracted position.

8. A quick-picking-up and slow-dropping relay comprising; a magnetic core, a high resistance winding and a low resistance winding on said core and connected in series, an armature, and contacts operated by said armature to shunt said low resistance winding when said armature is in its attracted position, to shunt said high resistance winding when said armature is in its retracted position, and shunt neither of said windings while said relay is being operated from its retracted to its attracted position.

9. A quick-pick-up and slow-drop-away relay comprising; a magnetic core; a winding on said core having a high-resistance-per-turn portion and a low-resistance-per-turn portion; an armature; and contacts operated by said armature to shunt said low-resistance-per-turn portion when said armature is in its attracted position, and shunt said high-resistance-per-turn portion when said armature is in its retracted position.

10. A quick-pick-up and slow-drop-away relay comprising; a magnetic core; a winding on said core having a high-resistance-per-turn portion and a low-resistance-per-tum portion; an armature; and contacts operated by said armature t0 shunt said low-resistance-per-turn portion when said armature is in its attracted position, shunt said high-resistance-per-turn portion when said armature is in its retracted position, and shunt neither of said portions when said armature is in a transitory position.

THOMAS J. JUDGE. 

